The present invention relates to guided-beam transducers such as are used in strain-gage type load cells. The invention is particularly useful for producing constant-strain, dual guided-beam transducers, and is therefore described below with respect to that application.
Transducers having constant-strain characteristics generally provide improved linearity and sensitivity, particularly creep properties, i.e., change in output as a function of time with constant load applied. Heretofore, single, non-guided beam transducers have been used to provide constant-strain characteristics. Single-beam transducers, however, generally perform more poorly than guided-beam transducers with respect to linearity and repeatability of output, hysteresis, criticality of the point of load application, and immunity from side loads and moments. A number of techniques have been proposed for imparting constant-strain characteristics to dual guided-beam transducers, but the constant-strain characteristics provided by such known techniques are merely approximations and not exact.
An object of the present invention is to provide a guided-beam transducer having constant-strain characteristics which are theoretically exact.
Another object of the present invention is to provide a novel dual guided-beam transducer of the folded-end type.